An image forming device such as a multi-function peripheral or a laser printer includes a fixing device to fix a toner image to a paper sheet. The fixing device transfers heat of a heater to the paper sheet through a fixing belt, for example, to fix the toner image transferred onto the paper sheet to the paper sheet. With this configuration, an image and a character are printed to the paper sheet.
In such a type of the fixing device, a pressing roller is pressed to a pressing pad disposed inside the fixing belt through the fixing belt, so that a nip portion, through which the paper sheet passes, is formed between the fixing belt and the pressing roller. Therefore, when the paper sheet passes through the nip portion, and the fixing belt and the pressing roller rotate, an inner circumferential surface of the fixing belt slides with respect to the pressing pad. Thus, the inner circumferential surface of the fixing belt is coated with a lubricant such as silicon oil in order to reduce frictional resistance between the fixing belt and the pressing pad.
However, the silicon oil is, for example, leaked out from the ends of the fixing belt and thus reduced in amount. Therefore, a sliding property between the fixing belt and the pressing pad is degraded as the device operates.